You have a duck bill on your drain in the back of the ref . This I would think is full of gunk. Take your rear panel off the back of the ref and reclean your inside drain and cut a corner off the duckbill ,after you clean it out .

The board is mounted in a box on the left side and has plastic stand offs like on the G E boards that holds there boards on. It's in the back of refrigerator. You just have to Neal down and take board out of box. This is a hard one to call as we no the drain is plug up. But that frost on the freezer control and water or frozen looking drops by fan makes me think its more than the drain. But saying that go with the cheapies way first. Try to see if cleaning drain again works.

Also anytime I see frost on food or on controls I would look for door that is not closing first.Both doors should shut at a 45 degree angle by themselves when let go.sometime kids do not shut the door right or some food product is in the way of one of the doors closing.Sometimes gasket need to be clean.Or front rollers need to be adjusted to get doors to shut at a 45 degree angle.All must be look at. And lay on floor and make sure gaskets are closing on bottom and sides.

There is also a air return on the bottom of that drain pan to the right that maybe plug up with ice.Maybe take some of the lower bins out in fresh food and make sure that you get all the ice out of there and make sure its clear before putting it back together.

I checked this on the freezer side the first time it froze up and it was iced up. I did let it thaw but I did not know it went through to the friedge side. Now, this time I thawed it I left it unplugged with a space heater inside the door for about 5 hours. I will check on the fridge side too.

Do I access it from the back or inside the freezer/fridge side? I apologize for all the questions but I look for the parts you mention on the diagram to see what I am looking for. I injured my back late last week and want to minimize the time I end up working on this due to pain.